Tank conveyance with movable baffles



July 6, 1955 J. J. WRIGHT 3,192,877

TANK GONVEYANCE WITH MOVABLE BAFFLES Filed March 28, 1963 4 Sheets-Sheet 1 1N VEN TOR JAW/5 J AAP/6,47

July 6, 1965 J. J. WRIGHT TANK CONVEYANCE WITH MOVABLE BAFFLES 4 Sheets-Sheet 2 Filed March 28, 1965 JAMfJ J AAP/GH? Bosa/umg, Sm

fraai/frs July 6, 1965 J. J. WRIGHT 3,192,877

TANK coNvEYANcE WITH MovABLE BAFFLEs Filed March 28, 1963 4 Sheets-Sheet 3 INVENTOR JMES J Mfg/6147' /ouoC/t, Chae-n4. #W4/Clon f-Wm July 5, 1965 .1.J. WRIGHT 3,192,877

TANK GONVEYANCE 'TH MOVABLE BAFFLES Filed March 28, 1963 4 Sheets-Sheet 4 70,6 Pfg-5.5097

IN VEN TOR 'J4/w55 .z AAP/6197 United States Patent Office s 192,877 TANK CONVEYANCEs WTH MVABLE BAFFLES James J. Wright, Bratenahl, Chio, assigner to Cleveland Technical Center, Inc., Cieveland, (Ehio, a corporation of Deiaware Filed Mar. 28, 1963, Ser. No. 26%,689 16 Claims. (Cl. MD5-36%) This invention relates to tank conveyances for transporting liquids, and more particularly to conveyances containing baffle means for reducing the tendency for liquid to surge and for dissipating kinetic energies of liquid surging in the conveyance. Vfhile the invention may be used advantageously in various types of conveyances, for convenience it will be discussed in connection with railroad tank cars, in which use it provides particularly important benets.

A railroad tank car not only must be capable of withstanding static forces resulting from the weight of the liquid which it carries, but also must be capable of withstanding dynamic forces arising from theV energy of the liquid when it surges in the tank due to shocks or accelerations imparted to the car. Shocks that could cause substantial surging of the liquid frequently occur during starting, transit and stopping of railroad cars. Thus, on starting a train, the locomotive usually sequentially takes upon the slack in the draft gear of each car so'that each car is started individually; therefore, in a long train of cars the locomotive often is traveling at a substantial speed when the last cars in the train begin to move with the result that such cars are started with a jerk. If the car is a tank car, this can cause considerable surging of the liquid in the car. During transit, the cars may be subjected to shocks in all directions arising from track and equipment conditions and to shocks in directions longitudinally of the car due to run-ins and run-outs when cars abruptly change speeds relative to adjacent cars, with attendant striking or jerking of draft gear. Shocks from these causes during transit are often of frequencies and magnitudes that can cause considerable surging of and development of substantial kinetic energies in the liquid.

In general, however, shocks capable of causing harmful surging of the liquid are most pronounced on stopping. Shocks of considerable magnitude can occur if the brakes are applied unevenly or too rapidly. The greatest shocks on stopping, however, usually occur during switching and like operations when the car strikes or is struck by one or more other cars. Even at switching speeds not considered to be excessive, impacts occur that result in decelerations of the car at rates greater than 20 gs (where g is the acceleration of gravity, or about 32,2 feet per second per second) and in corresponding shocks causing surging of liquid carried by the car. Deceleration and shocks of such magnitude can occur, for example, when a car traveling at substantial speed strikes -a string of heavily loaded cars having their brakes set and draft gear contracted so they form a substantially immovable object. An impact of this magnitude can result even if the switching speed is within the range of four to eight miles per hour considered acceptable; furthermore, it is impossible to avoid occasional impacts at speeds as high as fourteen miles per hour, with resulting higher decelerations and greater shocks capable of causing'substantial surging of the liquid in a tank car. While shocks developed on stopping are primarily longitudinal, lesser shocks may develop in vertical and transverse directions.

The surge-producing shocks which provide the vgreatest potential for damage are the greatest in directions longitudinally of the car and generally parallel to the direction of lacceleration (defined as a rate of change of velocity,

whether increasing or decreasing). Prevention of damage due to surging arising from shocks in these directions is more important and considerably more diiiicult than protection against vertical or transverse shocks.

Heretofore, it has been the usual practice to make tank car tanks strong enough not only. to withstand the static forces resulting from the weight of the liquid in the tank, but also to withstand directly the forces resulting from the liquid surging in the tank from shocks and accelerations like those discussed above. The tanks, therefore, usually are circular in cross section and have curved ends to give them strength. They have no internal baes, but rely entirely on the strength of the walls to resist the forces resulting from the surging liquid as well as from the Weight of the liquid.` This conventional shape of tank car tanks greatly restricts the volume of liquid which can be transported within the permissible clearance limits for the car.

While proposals have been made to use internal baiiles in tanks in various types of conveyances, in general the baffles have been connected to theV side or bottom Walls of the tanks and at locations at which undesirable concentrated stress and corrosion can occur, necessitating special precautions in the tank construction. Furthermore tanks embodying such baflies are diicult to clean because o the numerous crevices that occur at the connections of the baiies to the Walls. Moreover, the batlies have not been as effective as desirable in preventingsurging and dissipating the kinetic energy, and have added substantially to the cost of construction of the tanks.

Railroads often find that their requirements for different types of cars change because of changes in the relative amounts of diierent kindsV of commodities being shipped for economic or other reasons. For example, the need for tank cars lcapable of transporting liquids is presently increasing while the need for hopper cars capable of transporting solid commodities such as coal is decreasing. It is desirable to be able to convert unneeded hopper and similar cars into tank cars; However, this has not heretofore been possible because, although the walls of such cars are strong enough to withstand forces arising from the weight of static liquid in the car, the walls are not strong enough to withstand the forces resulting from surging liquid.

An object of the present invention is the provision of a conveyance for transporting liquids having .a tank containing internal `baliies that effectively minimize the tenden-cy of liquid to surge on the `application of :shocks -to the conveyance, Iand also effectively dissipate the kinetic Y energy resulting from surgingV liquids. A further object is the provision of 'a conveyance having a tank .that is generally rectangular in cross section and in longitudinal sec-` tion so thatit provides a large Volume Within the size limita-tions imposed on vehicles, which tank contains baie members that effectively minimize -the tendency of the liquid to surge yand dissipate the kinetic energy of the surging liquid. A further object is 'the provision of a conveyance h-aving therein movable batile members for minimizing the Itendency -of liquid to surge and for dissipating the kinetic energy of surging liquid. Another object is the provision of a tank type conveyance having internal bale members that `are readily removable. to permit repair, replacement, or cleaning of the bafiie members and to permit inspection, repair and cleaning of. the tank. A further lobject is -t-he provision of a construction permitting the conversion of railroad cars such as hopper cars to tank cars, and their reconversion to'hopper cars if desired, at a reasonable cost.

Further advantages, objects and a fuller understanding of my invention will become apparent from the following p Vtatiana-. 1 July 6,1965

description of preferred forms thereof, .reference being made to the accompanying drawings in'which:

FIGURE 1 is a perspective of a railroad tank car embodying the invention, converted from a standard hopper car;

FIGURE 2 is a longitudinal view ofthe car of FIGURE 1, parts being broken away to show the bathe members therein;

FIGURE 3 is a portion of a cross section `along line 3 3 of FIGURE 2 and to `a somewhat large scale;

FIGURE 4 is a detail showing a sealing layer that may be used to line and sealV the interior of the car against leakage;

FIGURE 5 is a somewhat diagrammatic longitudinal sectional elevation of another tank oar, converted from a hopper car, embodying the invention .but embodying a single row of movable baille members;

FIGURE 6 is a plan of the car of FIGURE 4, with the Vtop broken away and some of the bathe members removed to show the bathe member-supporting means;

FIGURE 7 is a cross section along line 7-7 of FIG- URE 5;

FIGURE 8 is a perspective yof one of the bathe members used in the embodiment of FIGURES 5 to 7 inclusive;

FIGURE 9 is a somewhat diagrammatic sectional elevation of a modiiied form of tank car embodying the invention, converted from a hopper car; partially iilled with bathe members;

FIGURE 10 is a plan of Vthe car of FIGURE 9 with the top broken away and most of the bathe members removed to show the bathe member-supporting means;

FIGURE 1l is a side elevation, with parts lbroken away, showing a railroad tank car embodying the invention, the car being designed to provide maximum liquid carrying volume within permissible size limitations and being substantially filled with transversely extending baihe members;

FIGURE 12 is an end elevation, with parts broken away, of the car of FIGURE 11;

FIGURE 13 is a longitudinal vertical section of another maximum volume ytank car embodying the invention, in which the car is substantially iilled wit-h vertically disposed bathe members;

FIGURE 14 is an end elevation, with parts broken away, of the car of FIGURE 13;

FIGURE 15 is a plan of the car of FIGURES 13 and 14, the top .being omitted to show the bathe members therein;

FIGURE 16 is a graph illustrating the ei'lcect of the liquid level on the dynamic pressures exerted on the top wall of the tank at the impacted end of a tank car that is subjected to impacts at a constant speed, when bathe members are used according to the invention; and

FIGURE 17 is a graph illustrating the dynamic pressures on the end walls and the top walls of tanks `at the impacted ends of cars -of the types shown in FIGURES 11 and l2, and 13 to 15 subjected to impacts at various speeds, (i) when bathe members `are not used and, (ii) when they are used according to the present invention.

FIGURES 1 to 4 illustrate a tank car that has been converted from a standard three door bottom opening hopper car comprising trucks l carrying wheels 2, snpporting .a lhopper body 3. The hopper body is made up of reinforced sidewalls 4, end walls 5, sloping lbottom end walls 6, hopper doors 7, 8 and 9, and intermediate sloping bottom walls 10 and 11. Parts thus far described are conventional.

The hopper body 3 of this car has been modified to form a tank 12 that is generally rectangular in cross section and in longitudinal section lby closing the open top of the tbody 3 with a top 14 that is fixed to the top edges of the side and end walls 4 and S. The top has a closure 15 which may be used for hlling purposes and, if large enough, may be used as .a man hole. Preferably, the top 14 also includes a hatch cover 16 removably fixed to the top to close a large `hatch 17 that permits greater accessibility to the interior of the car. Closure 15 and hatch cover 16 preferably are located generally centrally of the length of the tank since, as will be apparent later, there are no great forces exerted by the liquid -on this portion of the top wall. The car has also been modiiied by permanently welding shut the hopper doors 7, 8 and 9, and the interior of the car has been rendered liquid-tight. This is accomplished, as FIGURE 4 shows, .by lining the entire interior or the car with a layer 18 of suitable sealant material, which may be applied in the form of a solid layer and secured to the surfaces by adhesive, or which may be painted or sprayed on and permitted to solidify. The sealant is any one of several conventional materials that is not attacked by and will not contaminate the liquids to be carried in the car. The ltank 12 also has drain cocks 19, preferably located in the sealed hopper doors 7, 8 and 9, of the lower hopper portions, which thus act as sumps.

In order to minimize surging of liquid within the car, dissipate the energy of the liquid and prevent development of excessive liquid pressures within the car, the tank l2 of Ythe car is substantially filled with bathe members 2i). Each member 2li is a commercially available circular cross-sectioned 55-gallon steel drum, approximately 35 long and 23" in diameter, modified by having both ends removed. These members are disposed with their axes generally horizontal and generally transverse of the car. They are packed closely, but are capable of limited but appreciable independent movement relative to each other and to the tank 12. The bahle members or drums 20 are not in any way connected to any part of the car tank and are located merely by gravity and contact with adjacent bathe members. The drums in the upper layer are normally out of the contact with the top 14 of the tank l2. The drums are disposed so that they extend substantially entirely across the width of the tank, the reinforcing ribs 21 formed in the walls of the drums normally being staggered relatively to the ribs of adjacent drums as shown in FIGURE 3. These ribs tend to prevent adjacent bathe members from moving longitudinally relatively to each other, and hence from moving transversely of the car tank. The ribs also separate adjacent bathe members to permit passage of liquid therebetween, thus aiding in providing the tortuous path for liquid flow that results in the benets described later.

In service, the tank 12 is partially filled with liquid 22 to a depth so the level 23 of the liquid when the car is at rest and horizontal is a substantial distance below the underside of the top 14 of the tank, and most if not all of the bathe members 29 of the uppermost layer in the liquid are only partially immersed in the liquid as shown in FIGURE 2. In a generally hat topped car, of the size of an ordinary American hopper car, the free level of liquid 'should be no closer than about one foot below the underside of the top 14 of the car when the car is at rest and horizontal and in any event should be low enough to permita large proportion of the uppermost bathe members to protrude a substantial distance above the free level of liquid throughout its area. As will be explained later, the bathe members Ztl prevent substantial surging of the liquid in the car tank and also largely dissipate the kinetic energy of surging liquid even though the tank is subjected to substantial shocks in the longitudinal and other directions as described above.

Similar although somewhat lesser benefits result even if the car tank is not substantially completely iilled with bathe members. The embodiment of FIGURES 5 to 7 diagrammatically shows a tank car formed by converting a similar bottom opening hopper car into one having a tank 12. In this tank there is only a single row of baihe members 25 resting on a supporting frame 26. This frame comprises three generally horizontal beams 27 extending along substantially the entire length of the car tank and supported by vertical members 28 connected to beams 29 at the tank bottom. One of the bathe members 2S is Ei shown in FIGURE 8; it is an open-ended hollow cylindrical member formed of heavy gauge steel comparable to baffle members Ztl and of substantially the same dianteter, having a plurality of circumferential reinforcing ribs 31. Adjacent baffle members are arranged yso thatrthe ribs are in staggered relation; the ribs provide the advantages indicated previously. Each baffle member 25 is supported with its axis generally horizontal and extending transversely of the car, and is long enough to extend across substantially the entire width of the tank 12 as shown in FIGURE 7. The bathe members lill substantially the entire length of the tank, there being suthcient clearance to permit each baiiie member to move relative to other bathe members .and the tank for a limited distance- -for example, 2 inches-lengthwise of the tank. The baffle members are not connected to the tank or to each other.

Frame 26 supports baffle members 25 so that they are partially immersed in the liquid 22 and partially project above the free level 23 ofthe liquid. As in the previous embodiment, the freelevel of the liquid is a substantial distance below the underside of the top 14 of the tank 12 of the car tank, this distance being about one foot when the tank is filled to the preferred level. By suitable modification 'of frame 26 lshorter baiie members, suchas those of FIGURES 1 to 4, can be used.

FIGURES 9 and l0 show a tankY car also formed by converting a hopper car of the ysame type. The tank 12 of this .car contains two rows ofV baliie members 25 supported partially .by a frame 32 and partially by other baffle members 25 located between the end of the frame and the sloping bottom end walls 5 of the car. The frame 32, as shown in FIGURES 9 and 10, comprises three beams 33 each having a generally horizontal portion 34 extending for a major portion of the length of the car tank and two downwardly extending sloping end portions 35 terminatnig close to the sloping bottom end walls 6 of the tank car. Each beam 33 is supported by end portions 35 and an intermediate Iportion 36 from bottom beams 37 at the bottom of the car.

The baffle members 25 are like that shown in FIGURE 8 and extend generally horizontally and transversely substantially across the entire width of the tank 12 of the car. They are arranged in two rows to fill almost the enti-re length of the tank, with additional bafiie members filling the available 'space between the endrrnembers-35 of the supporting frame 32. T-he uppermost baliieA members 25, as in the preceding embodiments, are located a substantial distance below the underside of the top 14 of the tank and are partially immersed in the liquid 22, the free level 23 of-wln'ch is disposed a substantial distance below the underside of the top, Iso that the uppermost baille members protrude a substantial distance above the free level of'liquid. The tank car of FIGURES 9 and lO provides essentially the same types of benets as the tank car of FIGURES 1 to 4 in inhibiting surging of the liquid Vand dissipating kinetic energy of surging liquid. It is somewhat more effective than the embodiment of FIGURES to 7 since the baffle members adjacent the sloping bottom end walls 6 of the car of FIGURE 9 apparently aid in preventing upward Isurging lof liquid, but is somewhat less eiective than the embodiment of FIGURES 1 to 4.

The car of FIGURES V11 and l2 is an embodiment adapted to carry essentially the maximum volume of liquid that can be transported within the size limitations imposed by railroad car-clearance requirements. In this car the tank 41 is generally rectangular in cross section and in longitudinal sect-ion, comprising generally parallel and vertical side walls 42, generally parallel and vertical end wallsA 43, an essentially horizontal and flat top 44, a generally flat bottom 45 having two depending portions 46 on each side of center rail 47 to add to the volumetric capacity and also act as drainage sumps carrying drain cocks 48. The car has a'closure member 49 for filling purposes and a hatch cover 51 closing a hatch 52. The s-ide Walls 42 have vertical reinforcing members 53 in the usual manner. Since this car is specially built, it may be constructed to be leak-proof without the lining material of therst embodiment, although such material may be included if desired.

Members 54 bridge the depending portions 46 inthe tioor of the tank. The tank is substantially filled with open-ended tubular bathe members 25, like that of FIG- URE 8, disposed generally horizontally .and transversely of the tank and `extending substantially across the entire width of the tank Aas shown in FIGURE 12. The lowermost b'afiie vmembers are partially carried by the oor of the t-ank and by .the bridge members S4. The bafie members are closely packed together but are capable of limited movement relative to each other and to the tank; they are not connected to each other `or to the tank. The uppermost baille members are a substantial distance below the underside of the top 44 of the tank. The car is filled with liquid 22 to the free level 23 that is also a substantial distance below the underside of the top 44, this distance preferably being about one foot when the car is filled to capacity. The arrangement is such that the uppermost baie members 25 in the liquid lare partially immersed lin the liquid and partially extend above the free level of the liquid.

The car of FIGURES 13 to 15 inclusive Valso is designed to carry the largest volume of liquid possible within sim limitations. Tank 56 of this car is essentially rectangular in cross :section and inr longitudinal section and comprises generally vertical side walls 57 land end walls 48, a generally horizontal and dat top 59, and a bottom 61 formed with two depending portions 62 which add capacity and act as sumps carrying drain cocks 63. Vertical members 64 are fixed to the inner surface of the side walls 57; they stiften the Walls, space .balile members 65 from the -side walls, and make possible increased tank capacity. Batlle members 65, each Vof which may be essentially the same as the baffle member of FIGURE 8, extend substantially vertically -in the tank 56 :and thus transversely of the direction of travel of thev car. Members 65 are supported by the floor 61 and bridge members 66 extending'across depending portions 62. Balile members 65 are not connected to each other by the tank,

and are packed closely while being capable of limited but substantial movement relatively to each other .and to the tank. They extend to within a short distance of the underside of the top 59 of the tank, but are spaced therefrom.

The tank 56 is filled with liquid 22 to a free level 23 spaced ra substantial distance from the underside of the top 59 of the tank; the free level of liquid moreover is substantially below the upper ends of the baflie members 65. Preferably the free level of liquid is about one foot below the top wall 459 of the car and about six inches below the upper ends of the members 25.`

Y Operation Tests have shown that railroad cars embodying the invention satisfactorily withstand the effects of surging liquids even though the cars are so constructed that their walls will wiht-stand the static forces exerted by the weight if liquid' but not the dynamic forces resulting from surging liquid, in the absence of the baffle members of .the invention.

Actual tests on .a full sized tank car demonstrated the benefits of the invention. This car was converted from a three door bottom Vopening standard gondola car the tons. -age to the cars.

proportion of the uppermost drums protruded above the water level. The converted car weighed 63,300 pounds empty and 207,300 pounds filled, the water weighing 144,000 pounds. The carV was .successively impacted eight separate times at speeds ranging from 1.4 to 8.3 miles per hour against tive .box cars with their brakes locked, these cars having .a combined weight of 120 The impact tests showed no leakage and no dam- Ten holes, 1/s pipe size, drilled in vthe top wall along the left side of the car at intervals of 3l, with the two end holes 6 from the end walls, showed that at no impact did water spout from any hole further inward of the car than the second hole at the impacted end of the car, which hole was 37 in from the car end; this indicated that there was little dynamic vpressure developed even at the ends of the car tank, and no appreciable dynamic 4pressure in the central portions 0f the tank.

FIGURE 16 graphically illustrates the results of tests on a scale model of a railroad car e sentially identical with that shown in FIGURES 11 and l2. The car was moved on rails and impacted in aV .series of tests `at a s eed of 4 miles er hour against an immovable object,

with varying levels of water in the car. In FIGURE 16 the vertical ordinate indicates the increase in pressure, resulting from surging liquid, on the ytop wall immediately adjacent the end wall at the impact end of the car, while the horizontal ordinate indicates various levels of liquid in the car. The upper curve, marked no baille members graphically illustrates the increase in pressure on the top wall at increasing levels of liquid in the car, when the car contained no bellies. The lower curve illustrates the results when the car was impacted while filled with tubular vbaiiles arranged as in FIGURES ll and 12, and with water to various levels. `FIGURE 16 shows that the presence of the bailles caused a great reduction in the pressure exerted by surging liquid on the end portion of the Car so long as the level of liquid in the car was a substantial distance below the underside of -the top wall of the car, indicated by level P which was essentially the level shown in FIGURES 11 and 12; :and that when the car was iilled with water above this level, the pressure exerted by the surging liquid rapidly increased. FIGURE 16 thus indicates that the invention provides great benefits when the tank is tilled with liquid to a level not exceeding a critical level.

FIGURE 17 graphically illustrates the elects of baffle members in cars of the general types shown in FIGURES 11 and 12 and FIGURES 13 and 15. Impact tests were conducted on scale models essentially similar to those shown in FIGURES 11 and 12 and 13 to 15 and on a scale model containing no baille members. The horizontal ordinate represents the speeds in miles per hour at which in each case the car was impacted against an immovable object, and the vertical ordinate represents the increase in pressure in pounds per square inch resulting from surging liquid. In all cases the car was filled with liquid to the level indicated by point P on FIGURE 16. The two upper curves, representing the dynamic pressures exerted by surging liquid on the end wall of the tank at the impacted end of the car and on the top wall in the vicinity of such end Wall, indicate that the dynamic pressures increased considerably and substantially uniformly with increasing impact speeds when the car contained no baffle members. The two lines in the lower portion or" FIGURE 17 indicate that whenthe car was substantially filled with tubular baffle membersas in FIGURES 11 and 12 and in FIG- URES 13 to 15 the pressures on the end walls and the top walls of the tank at the impacted end of the car increased only slightly by surging liquids, even at impact speeds as high as 10 miles per hour. The benecial results of the baille members are substantially identical whether the Vbaille members are arranged as in FIGURES l1 and 12 or as in FIGURES 13-15, so the curves at the lower portion of FIGURE 17 represents the results from either arrangement.

While the manner in which the above embodiments operate in reducing forces of surging liquids in tank cars is not fully understood, it appears that the beneficial results indicated above occur due to a combination of cooperating factors. Apparently the subdivision of the body of liquid into numerous increments of relatively small volumes contained in and between the baille members causes the liquid in these small bodies of liquid to surge against the walls of the baille members rather than in a single large body against the walls of the tank when a substantial shock is imparted to the tank, so that numerous small surges result rather than one or a very few large surges of liquid. Furthermore, any surging liquid tending to move along the tank from these small bodies of liquid to others must follow a tortuous path, which tends to retard movernent of the liquid and inhibit surging.

The baille members which are partially immersed in and partially project from the liquid at its free level prevent the development of large surges or waves in the upper layers of liquid, and force most if not all of the liquid tending to move in these layers to travel around rather than over the bale members, which factor also inhibits surging of such liquid.

Moreover, the kinetic energy of any liquid that does surge is largely dissipated by the work performed by the liquid in moving the baille members against the forces resulting from the inertia of relatively heavy baille members, each of which has a speciiic gravity substantially greater than that of the liquid, and from the friction between .the liquid and the bale members and between the adjacent baille members themselves. Any surging effect tending to travel from one end of the tank to the other is largely dissipated by work expended by sequentially moving the various baille members along the length ofthe tank. As indicated, although the baille members are closely packed, they can and do move independently of each other and of the tank; this was evident during the tests the results of which are graphically shown in FIGURES 16-17, ,since the scale model cars had transparent sides. Each baille member is capable of substantial, although limited movement'during a severe shock to the tank; such movement, although preferably amounting to only a few inches, is sulllcient greatly to dissipate the kinetic energy of surging liquid as described above. The baille members thus are energy dissipative in that on movement they dissipate kinetic energy of the liquid rather than storing the kinetic energy applied to them and returning it in the opposite direction, as would an elastic or resilient baille system.

Because ofthe interaction of the above factors, it appears that the effects ofthe shock imparted to the tank are transmitted over a substantial period of time to and through the liquid in the tank. The dynamic forces to which the tank is subjected from moving liquid thus are considerably less in magnitude and applied to the tank over a considerably longer time than would otherwise be the case, so that the stresses developed at the tank are considerably less than in tanks not containing baille members according to the invention.

The tanks can be easily cleaned since there need be no crevices or pockets resulting from connections of baille members to the tank in which can lodge materials that should be removed. If desired, the baille members themselves can be removed from the tank for inspection, cleaning or repair, although in general this is not necessary. The baflle members themselves can be made and installed at low cost. The vehicle tanks also can be specially made at reasonable cost, or as indicated above can be economically converted from other vehicles, since the walls of the tanks need not be made strong enough so that the walls above withstand the forces of surging liquids.

The present invention also makes possible tank vehicles having much larger capacities within railway clearance limitations than was heretofore possible. Thus, the tank cars disclosed above have liquid-carrying volumes two or lmore times as great as the volume available for carrying liquid in a conventional railroad tank car.

Those skilled in the art will appreciate that the invention may be employed in conveyances other than those specifically disclosed herein and that various changes and modifications other than those indicated above can be made in the invention without departing from the spirit and scope thereof. The essential characteristics of invention are defined in the appended claims.

Iclaim:

1. A conveyance for transporting liquids comprising -a tank having an interior adapted to contain a body of liquid of substantial depth and having a free surface, the proportions of said tank interior being such that when said tank is subjected to acceleration in the direction of Iits length Ithe liquid tends to surge therein, means for reducing the forces `on the tank from surging liquid comprising a plurality of baille members each `of a specific gravity substantially greater .than that of the liquid and including an outer Wall defining a cross section of substantial area and a generally hollow interior and having an opening in the wall permitting liquid to ttlow substantially freely into and out of' said baille member, and means supporting said baille members so that lthey can move generally parallel to the direction `of acceleration Iof :said tank independently of each other and said tank and so that when the free level of liquid is at rest said Ibaille members are only partially immersed in said liquid with portions thereof extending below the free level of the liquid and other portions thereof extending -above the free level of the liquid, said baille members being disposed -in relatively close proximity to each other generally throughout the area of the free level of the liquid.

2. A conveyance for transporting liquids :comprising a tank having an interior adapted to contain a body of Iliquid of substantial depth and having a free surface, the proportions of said tank interior Ibeing such that when said tank is subjected to acceleration in the direction of its length the liquid tends to surge therein, means for reducing the forces on the tank from surging liquid comprising a plurality of baille members each of a specific gravity substantially greater than that of the liquid and having an outer wall defining a cross section of substantial area and a generally hollow interior and having an opening in 4the wall permittin-g liquid to flow substantially freely into and out of said baille member, and means for supporting said baille members so they are completely immersed in said liquid in said tank and so that they can move generally parallel to the direction of acceleration in said tank independently of :each other and said tank, said lbaille members being disposed :in relatively close proximity to each other generally throughout a cross section of the tank parallel to the direction of acceleration. t

3. A conveyance for transporting liquids comprising a tank having an interior adapted to contain a body of liquid of substantial depth :and having a free surface, the proportions of sai-d tank interior being such that when said tank is subjected .to acceleration in the direction of its length the liquid tends .to surge therein, and means for reducing the forces on the tank from surging liquid comprising a plurality of baille members each of a specific gravity substantially greater than that of the liquid and including an outer wall defining a cross section of substantial area and .a generally hollow interior and having an opening in the Wall permitting liquid to flow substantially freely into and out of said baille member, the interior =of said tank below the free level of liquid being substantially filled with said baflle members arranged in relatively close proximity so that they are substantially located by adjacent bae members while permitted limited movement independently :of each other an-d said tank in a direction generally parallel to said direction of acceleration. i

4. A conveyance for transporting liquids comprising the proportions yof said tank interior being such that Y when said tank is subjected to acceleration in .the direction lof. its length the liquid tends to surge therein, means for reducing the forces on the tank from surging liquid comprising a plurality of baille members each `of a specific gravity substantially greater than that of the liquid and including an outer Wall defining a generally circular cross section and a hollow interior and having an opening in the wall permitting liquid to flow substantially freely into and out of said baille member, and means lsupport-ing said baffle members so that they can move generally parallel .to the direction -of acceleration of said tank independently of each other and said tank and so that when the free level yof liquid is yat rest said baille members are only partially immersed in said liquid with portions thereof extending below the free level of the liquid and 4other portions .thereof extending above the free level of the liquid, said baille members being :disposed in relatively close proximity toeach other generally throughout the area of the free level of the liquid.

5. A conveyance for transport-ing liquids comprising a tank having an interior adapted to contain a body of liquid of substantial depth and having a free surface, the proportions of said tank interior being such that when said tank is subjected to acceleration in the direction of its length the liquid :tends to surge therein, said means for reducing the forces on the tank from the liquid surging in the tan-k comprising a plurality of baille members each of a specific gravity-substantially greater than that of the liquid and having an outer Wall defining an exterior of generally circular cross section and a vhollow .interior and having an opening in the wall permitting liquid to flow substantially freely into and out of said baffle member, the interior of said tank below the free level of liquid being substantially filled with said baille members arranged in contacting relation with generally circular cross sections of said baille members extending generally parallel to the direction of acceleration of said tank, said baille members being -capable of limited movement in a direction generally parallel to said direction yof acceleration.

`6. A conveyance for transporting liquids comprising a tank having :an interior adapted to contain a body of liquid of substantial depth and having a free surface, the proportions yof said tank interior being such that when said tank is subjected to acceleration in the direcf tion of its length the liquid tends to surge therein, and means for reducing the forces on the tank from liquid surging in the tank comprising a plurality of baille members cac-h of a specific gravity substantially greater than that of the liquid .and having an outer Wall defining an exterior of generally circular cross section and a hollow interior and having an `opening therein permitting liquid t-o flow substantially freely -into and out of Isaid baille member, the interior of said tank up to the free level yof liquid being substantially Ifilled with said baffle members arranged in contacting 4relation with generally circular cross sections of said baille members extending generally parallel to the direction of acceleration of said tank and uppermost baflle members being disposed with their lower portions immersed in the liquid and with their upper portions extending above the free surface of :the liquid, said baille members being capable of limited movement in a .direction generally parallel to said direction of acceleration.

'7. A conveyance for transporting liquids comprising a tank having an interior adapted to contain a body of liquid of substantial depth and having a free surface, the proportions of said tank linterior being such that when said tan'k is subjected to accelerations in the direction lof tits length the liquid tends to surge therein, means for reducing the forces on the tank from liquid surging in said tank comprising a plurality of elongated baille members each being generally circular in cross section :and having a hollow interior .and openings in its ends permitting liquid to ow substantially freely through said baffle member and being of a specific gravity substantially greater than that of the liquid, said bathe lmembers being disposed with the axes of their generally circular cross sections extending generally transversely to said direction of acceleration of said tank, said baie members being disposed in `close proximity to each other to occupy substantially the entire area of the free level of liquid when at rest in said tank .and 'being partially immersed in said liquid with portions thereof extending into and other portions thereof extending `from the liquid, and means `for supporting said members vfrom below the members to permit them to move independently of each other and of said tank in a direction generally parallel to the direction of yacceleration of said tank.

8. The yconveyance of lclaim 7 in which `said baiiie members have external projections extending substantially around the circumferences thereof, theV projections on adjacent baffle members being offset.

9. The conveyance of claim 7 in which said baffle members are disposed with their faxes ygenerally horizontal.

1t?. The conveyance of claim 9 in which said bafiie members -are long enough to extend substantially the full width of said tank.

1-1. The conveyance of claim 7 in which said baffle members are disposed with their axes generally vertical. 12. The `conveyance of claim 7 in which said conveyance is a railroad tank car in which said tank is generally rectangular in its longitudinal section and cross section.

13. A conveyance for transporting liquids comprising a tank having an interior adapted to contain -a body of liquid of substantial depth and having a free surface, the proportions of said tank ybeing such that when said tank is subjected to acceleration in the direction of its length the liquid tends to surge therein, and means for reducing the forces on the ytank from liquid surging in said tank comprising a yplurality of elongated bafiie members each being generally circular in 4cross section and having a hollow interior and openings in its ends permitting the liquid to tiow substantially freely through said batlie member and `being of a specific gravity substantially greater than that of the liquid, said bae members being disposed with the axes of their ygenerally circular cross sections extending transversely to said direction of acceleration to occupy substantially the entire portion of said 4tank lled with the liquid, at least several of said baffle members being partially immersed in the liquid with substantial portions thereof extending below and other substantial portions thereof extending above the free level of liquid in said tank when the liquid is at rest, said bande members being capable of moving independently of each other and of said tank.

14. The conveyance of claim 13 in which said bathe members are disposed with their axes generally horizontal.

15. The conveyance of claim 13 in which said bathe members are disposed with their axes generally vertical.

16. The conveyance of claim 13 in which said conveyance is a railroad tank car in which said `tank is generally rectangular in its longitudinal section and cross section.

References Cited by the Examiner UNITED STATES PATENTS 2,724,597 ll/SS Fowler 280-5 2,840,259 6/58 Steidl 220-22 ARTHUR L. LA POINT, Primary Examiner.

LEO QUACKENBUSH, MILTON BUCHLER,

Examiners. 

1. A CONVEYANCE FOR TRANSPORTING LIQUIDS COMPRISING A TANK HAVING AN INTERIOR ADAPTED TO CONTAIN A BODY OF LIQUID OF SUBSTANTIAL DEPTH AND HAVING A FREE SURFACEK THE PROPORTIONS OF SAID TANK INTERIOR BEING SUCH THAT WHEN SAID TANK IS SUBJECTED TO ACCELERATION IN THE DIRECTION OF ITS LENGTH THE LIQUID TENDS TO SURGE THEREIN, MEANS FOR REDUCING THE FORCES ON THE TANK FROM SURGING LIQUID COMPRISING A PLURALITY OF BAFFLE MEMBERS EACH OF A SPECIFIC GRAVITY SUBSTANTIALLY GREATER THAN THAT OF THE LIQUID AND INCLUDING AN OUTER WALL DEFINING A CROSS SECTION OF SUBSTANTIAL AREA AND A GENERALLY HOLLOW INTERIOR AND HAVING AN OPENING IN THE WALL PERMITTING LIQUID TO FLOW SUBSTANTIALLY FREELY INTO AND OUT OF SAID BAFFLE MEMBER, AND MEANS SUPPORTING SAID BAFFLE MEMBERS SO THAT THEY CAN MOVE GENERALLY PARALLEL TO THE DIRECTION OF ACCELERATION OF SAID TANK INDEPENDENTLY OF EACH OTHER AND SAID TANK AND SO THAT WHEN THE FREE LEVEL OF LIQUID IS AT REST SAID BAFFLE MEMBERS ARE ONLY PARTIALLY IMMERSED IN SAID LIQUID WITH PORTIONS THEREOF EXTENDING BELOW THE FREE LEVEL OF THE LIQUID AND OTHER PORTIONS THEREOF EXTENDING ABOVE THE FREE LEVEL OF THE LIQUID, SAID BAFFLE MEMBERS BEING DISPOSED IN RELATIVELY CLOSE PROXIMITY TO EACH OTHER GENERALLY THROUGHOUT THE AREA OF THE FREE LEVEL OF THE LIQUID. 